Cheryl Strayed’s heart-rending 2012 account of her 1,100-mile hike along the Pacific Crest Trail presented no shortage of obstacles en route to the bigscreen, not least in the way it used the great outdoors as the backdrop for a resolutely interior journey. But director Jean-Marc Vallee, screenwriter Nick Hornby and star-producer Reese Witherspoon have met the challenge head-on with imperfect but rewarding results in “Wild,” a ruggedly beautiful and emotionally resonant saga of perseverance and self-discovery that represents a fine addition to the recent bumper crop of bigscreen survival stories. Resting squarely on Witherspoon’s sturdy shoulders (along with the back-crushing backpack she carts around throughout), the Fox Searchlight release should be admiringly received by critics and arthouse audiences come Dec. 5.

Still, the film could face some competition from John Curran’s equally accomplished “Tracks” (set to open Sept. 19 Stateside), this year’s other adaptation of a bestselling woman-in-the-wilderness memoir, and it remains to be seen whether it can improve on the modest commercial performance of films like “Into the Wild,” “127 Hours” and “All Is Lost.” Of those three particular forebears (all of which also screened under appropriately scenic, high-altitude conditions at the Telluride Film Festival), “Wild” bears the closest resemblance to Sean Penn’s 2007 drama, not only in their similar titles, but also in the way both films employ a jagged flashback structure to peel back the painful circumstances that led a young college grad in the ’90s to retreat from society and walk a very lonely road.

Unlike “Into the Wild’s” Christopher McCandless, of course, Cheryl Strayed (born Cheryl Nyland, before she chose her wayward-sounding surname) lived to tell the tale, and she did so with no shortage of brutal honesty and hard-bitten humor — an element that finds a natural complement in Hornby’s own sharply funny instincts as a writer, making him a less counterintuitive choice here than some might expect. Indeed, the filmmakers have arguably mastered the material’s subtle, sardonic insights more so than its big emotional moments, most of which involve Strayed’s beloved mother, Bobbi (Laura Dern), whose death from lung cancer at the age of 45 set off her 22-year-old daughter’s startling downward spiral into sex and heroin addiction, culminating in the end of her marriage. In condensing the book into a fleet drama that clocks in at just under two hours, Hornby has moved Bobbi’s tragic decline from the beginning of the story to the middle — a shrewd decision that nonetheless feels a bit too calculated in the execution, too neatly arranged to maximize the film’s slow-building emotional crescendo.

Still, “Wild” is never less than involving as it follows Witherspoon’s Cheryl from the Mojave Desert, in the summer of 1995, to the Oregon-Washington border more than three months later, deftly maneuvering between her past and present sufferings along the way. The film gets some wry comic mileage out of her misguided early decision to strap on an enormous, unwieldy backpack, which is so heavy that a fellow hiker christens it “the Monster” — just one of many examples of how ill prepared Cheryl is for this particular trip, despite her tough, resilient attitude and cross-country training. Slowly she plods her way northward, dropping expletives with every step, subsisting on oatmeal that she heats on a small gas-powered stove, fending off the occasional rattlesnake, and trying to stifle the inner voice that keeps telling her, “You can quit anytime.”

But she presses defiantly onward, even when she finds herself on a dusty 20-mile walk to a water tank that turns out to be empty, or when she veers into snow-covered mountain terrain that takes an especially rough toll on her too-tight boots and cracked, bloodied toenails. (That grotesque image aside, Vallee is more inclined to linger on his Oregon landscapes, captured in awe-stirring but never self-admiring widescreen images by d.p. Yves Belanger, using handheld digital cameras with an emphasis on natural light.) Along the way, Cheryl’s agony and tedium are relieved by kind, encouraging strangers; by the meaningful quotes from Emily Dickinson, Robert Frost and James A. Michener that she scribbles in her journal (and which appear a bit too frequently onscreen); and by the care packages she receives every few hundred miles or so from Paul (Thomas Sadoski), the most supportive ex-husband a woman could hope for.

The painful disintegration of Cheryl’s marriage, accelerated by her frightening if not entirely convincing transformation into a heroin-shooting nymphomaniac, is presented as a direct result of Bobbi’s death, at which point “Wild” reveals itself to be, among other things, a mother-daughter love story. The film seeks to convey the full trauma of Cheryl’s loss through flashbacks to happier times, revealing Bobbi (wonderfully played by Dern) as something of a survivor herself — a woman who fled an abusive marriage and raised two kids, including Cheryl’s younger brother, Leif (Keene McRae), on her own. (Strayed’s real-life sister, Karen, has been dropped from the movie entirely.) When Bobbi is shown going back to school to earn a belated bachelor’s degree, somewhat embarrassing Cheryl by attending the same Minneapolis university, the contrast between cynical, hard-edged daughter and sunny, optimistic mother is fully felt — but so, too, is an unconditional sense of mutual devotion.

It’s no surprise that the versatile Vallee, who recently directed two Oscar-winning performances in “Dallas Buyers Club,” has elicited from Witherspoon an intensely committed turn that, in its blend of grit, vulnerability, physical bravery and emotional immediacy, represents easily her most affecting and substantial work in the nine years since “Walk the Line.” (The actress’s still-youthful appearance helps fudge her 12-year age gap with the 26-year-old Cheryl, as well as her only nine-year age gap with Dern.) Nor is it a surprise that Vallee, whose bracingly sharp editing on “Dallas Buyers Club” was one of that film’s more unsung virtues, has applied similarly bold cutting-room strategies here.

Once again working under the pseudonym of John Mac McMurphy (and sharing duties with Martin Pensa), Vallee jumps compulsively between narrative tracks; certain individual shots are sustained for just a split second, which creates a whispery, hallucinatory effect in conjunction with the film’s richly detailed soundscape. It’s here, however, that “Wild” begins to feel more constructed than fully realized, its abrupt narrative transitions relying on convenient visual parallels and memory-jogging song choices (in lieu of a score) rather than on intuitive storytelling decisions. When Cheryl is shown panting her way through a patch of dimly lit undergrowth, the sudden cutaways to her panting her way through a rear-entry sex scene seem more distracting and heavy-handed than anything else.

Incidentally, Vallee and Hornby’s insistence on presenting their protagonist as a fully formed sexual being is one of the film’s most refreshing qualities, and the truest mark of its fidelity to its ardent and lusty source material. As an attractive woman in her 20s traveling alone, Cheryl is acutely aware that every strange man she encounters is a potential predator — whether it’s the kind farm worker (W. Earl Brown) who offers her a hot meal and shower, or the fellow traveler who turns out to be a very real threat. But Cheryl is neither a passive victim nor a saint, and in a film of quietly understated moments that often prove more impressive than the whole, few are as telling as the one where she casually spies on a male hiker (Kevin Rankin) emerging nude from a dip in the river — a rare example of the female gaze at work in American movies.

“You sound like a feminist,” says a journalist (Mo McRae) who stops to interview Cheryl, the first “lady hobo” who’s crossed his path. It’s an amusing scene, and a slyly self-aware one as well: While “Wild” will surely be praised in the coming months for having a strong, well-written, flesh-and-blood female at its center, it’s to the film’s credit that it wears this badge of honor with a lightness that in no way undermines its sincerity.

I hope this gets to theatres so the masses can see it before the Oscars. All the Oscar contenders I’ve seen thus far are flawed in minor or major ways, many in their storylines – this one sounds like a good story with two potentially Oscar-worthy female performances.

Do you know how many films about fathers and sons female audiences are happy go to (Star Wars and Boyhood come to mind)? Glenn C’s comment reinforces the sad perception that women are interested in stories about women or men while men are only interested in stories with male protagonists because the experience of men is deemed to be universal while the experience of women (a majority) is deemed to be particular or “special interest”.